1. Field of the Invention
This invention relates to a fast-connecting joint for corrugated pipes, particularly to one having its main body provided with an inner recessed annular wall, which is provided with an annular slope for mutually combined with projections of curved petals of an engaging member. When a corrugated pipe is quickly inserted in the engaging member and locked by the curved petals, it is strongly fastened with the fast-connecting joint, as the connection is to be tightened more and more if the corrugated pipe is continuously pulled outward by force.
2. Description of the Prior Art
As disclosed in a Taiwan patent No. 545543 “Connecting tube for corrugated pipes”, a first conventional connecting tube for corrugated pipes is provided with a main body and a locking member mounted on an outer surface of the main body, enabling an engaging gap formed between the main body and the locking member at two ends of the main body so that one end of a corrugated pipe can correspondingly and tightly fits in the engaging gap, with the locking member kept fixedly in one of plural annular grooves of the corrugated pipe, finishing assembly of the corrugated pipe with the connecting tube.
However, it has disadvantages that the locking member is mounted around on the outer surface of the two end sections of main body, so the outer diameter of the main body is such enlarged to cost a little more. Moreover, if plural little corrugated pipes are to be inserted in a big one to be combined with the connecting tube, the locking member will become an obstacle for such an operation. Secondly, in order to keep the locking member effectively elastic, the locking member cannot be too thick to have elasticity; but, on the contrary, with an insufficient thickness, the locking member is apt to get broken.
A second conventional connecting tube for corrugated pipes, as shown in FIG. 1, includes a main body 1 provided with a through hole 10 for an engaging tubular member 11 to fit tightly therein for liquid to flow through. The engaging tubular member 11 is formed integrally, provided with a through hole 110, a plurality of petal-shaped locking members 111 formed continually around its rear portion, and a tapered end 112 extending outward from each locking members 111 for tightly fitting with an end of a corrugated pipe. As the main body 1 and the engaging tubular member 11 are independently made and have to be combined together by glue, the manufacturing cost is undoubtedly increased.
And, as shown in FIGS. 2˜4, a third, a fourth and a fifth conventional connecting tubes for corrugated pipes commonly include a main body 2 provided with a through hole 20 and an engaging member 21 is integrally shaped together with and in the main body 2, with plural lengthwise gaps 22 formed both in the main body 2 and the engaging member 21. However, in constructing a building, when concrete is pumped upon a corrugated pipe jointed with the connecting tube 2; the damp concrete may permeate into the connecting tube 2 through the gap 22, possible to keep the wire inside the corrugated pipe badly affected by the humidity.
Moreover, a Taiwan patent of No. 093123761 titled “QUICK-TO-CONNECT JOINT FOR FLEXIBLE HOSES” disclosed by this inventor is mainly provided with a main body formed integrally, and plural elastic locking petals similar to those in this invention. But, it is still not so suitable for diverse environments and requirements.